Apparatus for transforming electrical energy.



PATENTED JAN. 31, 1905.

P. G. HEWITT.

APPARATUS FOR TRANSPORMING ELECTRICAL ENERGY.

APPLICATION FILED SEPT. 24, 1902.

Patented January 31, 1905.

IJNTTED STATES PATENT EEIcE,

PETER COOPER l-IEVITT. OF NEW YORK, N. Y., ASSIGNOR, BY MESNEASSIGNMENTS, TO COOPER HEWITT ELECTRIC COMPANY, A COR- PORATION OF NEWYORK.

APPARATUS FOR TRANSFORMING ELECTRICAL ENERGY.

SPECIFICATION forming part of Letters Patent No. 781,603, dated January31, 1905.

Original application filed April 25,1902, Serial No. 104,608. Dividedand this application filed September 24, 1902. Serial No. 124,624.

To (t// 2071 0111.- Z't may concern:

le it known that I, P E'IER (loorEn H Ewrr'r, a citizen of the UnitedStates, and a resident of New York, in the county of New York and Stateof New York, have invented certain new and useful Improvements inApparatus for 'ilranst'orming Electrical Energy, of which the followingis a specification.

I have found that when an inclosed gas or vapor of suitable characterand density contained within a holder of suitable character anddimensions and having appropriate electrodes is connected in an electriccircuit there will be opposed to the passage of electric current aninitial resistance which may be overcome by an electromotive force ofsuiiicient value, the gas or vapor then serving as a conductor acrossthe gap in the metallic circuit, when the proper conditions of currentare supplied. This initial resistance appears as it a self-createdelectrical resistance phenomenon at the negative electrode, which onbeing overcome removes itself without any appreciable energy loss. Theresistance which the gas or vapor shall olfer to the current during theperiod of discharge may be made of practically any desired value withinwide limits, while the initial resistance above referred to can also bemade of any desired value each independently of the other. In otherwords, it is possible to so construct an apparatus of this sort as topresent initially a very high resistance to the passage of the currentand to present a very low resistance to the current after it has oncebeen established through the apparatus. Should other conditions berequired, both these factors may be varied by altering the constructionof the apparatus in the first instance. Assuming, however, a lowresistance during the discharge period and a desiredinitial resistance,the amount of work done in the vapor-gap is practically very small.Accordingly an apparatus of the kind described can be econo1nically usedin place of a spark-gap, possessing, by reason of the features abovementioned, a very great advantage over the ordi nary air-gap and a stillgreater advantage over a W'ehnelt interrupter. The described factorshaving once been lixcd may be kept at their normal value by maintaininga constant temperature of the inclosed gas or vapor. The means formaintaining such a temperature as well as the means for controlling anddetermining the other factors hereinbefore mentioned are fully set forthin certain patents issued to me on the 17th day of September, 1901. Ifdesired, special means for maintaining a constant temperature may beapplied to the apparatus when it is used in place of a spark-gap.Inasmuch as the electrodes remain practically unchanged by rep ated useand the whole apparatus is substantially unaltered, a single apparatuswill operate without any need of attention or repair. Should it bedesired to provide a higher initial resistance, so as to increase therise of potential in the discharge-oircuit, a new apparatus can besubstituted calling for such higher potential at the start; but this newapparatus may, like the lirst, consume little or no current during thedischarge period. These elecric circuit-ln-cakers may be used in seriesor parallel, and in case it is notdesired to have the initial resistanceto starting so great it may be modilied by starting-bands at theelectrodes, as described in my patents, and in case it is desired tooperate several breakers in parallel they may be timed by connecting thestarting bands or groups thereot' together. In these respects thedescribed apparatus is superior to the ordinary air-gap, in using whichit is necessary to keep the terminals of the conductors or balls smoothand polished and in which any increase in the initial resistance (as bythe separation of the balls or conductors) also entails an increase ofresistance during the period of discharge, and, further, the resistanceduring the discharge period may be lower and is far better than a\Vehnelt incrrupter on account of the great loss of energy in the\Vehnelt interrupter.

Another feature of my apparatus is that the gas between the electrodesacts as a true vapor -conduct0r after the circuit is once establishedthrough the vapor, and when this conductor is made of very lowresistance practically a short circuit is formed. Since thevapor-resistance factors are known and the conditions they are subjectto, the action can always be depended upon. By the passage of currentthe electrical pressure orvvoltage is lowered to a point where theresistance to starting re-forms, whereupon the checked current rebuildsor re'establishes itself, its electrical pressure rising until thebreakingdown pressure is again attained, after which the same successionof actions are repeated.

By utilizing the described apparatus in the manner indicated periodiccurrents of high frequency can be produced by reason of the fact thatits action is very quick and uniform. It is especially adapted to thework of creating currents of definite time periods and rapidalternations. I have found, for instance, that with a device consistingof an inclosed mercury vapor organized in the manner described in mypatents above referred to and provided with a condenser and a reactivedevice suitably placed and adjusted with reference thereto it ispossible to produce such currents, the action being in the firstinstance to apply to the terminals of the vapor-gap apotential'dilference sufficient to overcome the initial resistance,whereupon a rapid fall of potential takes place until it reaches a pointwhere it is insufficient to overcome the reduced resistance at thevapor-gap. At this point the current ceases to flow, the break incurrent-flow being abrupt on account of the immediate reestablishment ofthe initial resistance of the vapor. Thereafter the applied potentialrises until it reaches the breaking-down pressure of the initialresistance and then the same cycle of operations is repeated. Theintermittent or vibratory currents produced in the circuit by thecircuitbreaker thus described may be applied to use in the vapor or gasgap itself, or they may be applied to other apparatus, or to bothsimultaneously. For example, one application of the present inventionwould be to serve the purposes of furnishing a periodic current forwireless telegraphy and another for producing rapidly-varying currentsfor the purpose of producing light by induction, and still anotherapplication would be that of producing light, say, in the vapor-gapitself by means of. successive electrical impulses of relatively highelectromotive force, causing a high illumination of the vapor or gas atsuch rapid intervals that the physiological impression is that ofcontinuous illumination. In making the last-named application of myinvention 1 cause the intermittent currents produced by the intermittentaction of my apparatus to act upon the vapor in the gap in such a way asto produce a brilliant light. To this end the density of the vapor andthe dimensions of the container are suitably proportioned to each otherfor this purpose, as set forth in a general way in my patents ofSeptember 17, 1901; but whereas in the inventions set forth in the saidpatents the vapor is intended to be affected by a flow of current ofgiven value at a certain potential the purpose in the present instanceis to affect the gas or vapor by an intermittent flow of a current ofpractically the same value, but of higher potential, the energyrepresented by the intervals between the impulses being intermittentlywithdrawn from action and reappearing in the form of an increasedquantity in the rapid periodic currents. The result is an increasedbrilliancy on the part of the lamp due to this increased consumption ofenergy per unit of time, while the effect upon the eye becomes that of alight due to a continuous flow of current of greater quantity. Y

In the accompanying drawings, illustrating an application of myinvention, Figure 1 is a diagram showing a general organization of theapparatus. Fig. 2 shows a modification, and Fig. 3 is a theoreticaldiagram.

Referring to the drawings, 1 represents any convenient source ofelectrical energysay, for instance, a continuous current-generator,(which for convenience it may be assumed in this particular instance tobe of three thousand five hundred volts.)

2 and 3 represent main conductors leading from the generator.

4 represents an electric lamp of the character described in my patentshereinbefore referred to. This is connected at any convenient pointbetween the conductors 2 and 3.

A condenser 5 or other suitable device or means for affording anelectrical capacity is connected across the terminals of the lamp 4. Aninductive resistance 6 is connected in the line 2 between one plate 7 ofthe condenser 5 and the source. 1 of current. It is to be understoodthat by referring to a condenser I mean to include other suitable meansfor securing the requisite electrical capacity.

Assuming that the circuit of the generator is closed by the switches 9and 10, there will be asudden rush of current through the lines 2 and 3,tending to charge the plates 7 7 of the condenser 5., Theinductor-resistance 6 opposes a counter electromotive force to theapplied electromotive force, thus temporarily resisting the flow ofcurrent beyond that re sistance. The condenser 5 thus becomes grad uallycharged as the electromotive force at its terminals rises. Assuming thatthe lamp 4: will be traversed by a current under the influence of adifference of potential of three thousand five hundred volts, then assoon as the condenser 5. has attained its charge a current will traversethe lamp; but the moment such current does traverse the lamp thedifference of potential at its terminal is enormously reduced,Practically it may be made which the intervals follow each other.

7 tated by the use of a band H, placed in the l be repeated, causingrapidly-succeeding im- 1 pulses of current to traverse the lamp.succeeding impulse will be at a potential of, say, three thousand fivehundred volts. and the light emitted by the lamp will be of a brilliancydue to the product of the average voltage into the current during thesuccessive time intervals of currentflow. characteristic of these lampsthat they may be constructed not to pass an appreciable amount ofcurrent below a given voltage, which can be predetermined, and thereforeat the end of certain definite periods the current ceases to pass andthe light goes out. Accordingly the lamp has a definite consumptionperiod between the extreme higher limit of applied electromotive forceand the lowest limit at which the lamp will taltecurrent. hat isperceptible to the eye is the luminous vibrations due to thesesuccessive passages of current, the intervals of no current beingundiscernable by reason of the rapidity with The period of the condensermay be further retarded by an inductance device placed in thecondenser-circuit. An additional condenser- 12, placed between thesource and the condenser 5, may serve to assist the speed of charge anddischarge through the inductance 6. A similar inductance 6' may beincluded in the branch 3, if desired.

In my lamps the starting 18 usually facilineighborhood of the negativeelectrode upon the exterior of the lamp and connected by a conductor 15with the positive electrode or the conductor leading thereto and isuseful where lower initial voltages are to be used. By inserting theprimary coil 16 of a converter 17 in one of the conductors-for instance,3, as shown in Fig. 1 an alternating current may be produced in asecondary circuit 18, which in turn may beused for any desired purpose.The primary coil 16 in this case may be utilized as the inductancedevice referred to above for retarding the period of thecondenser-circuit.

In Fig. 2 I show the primary 16 of the converter 17 connected up betweentwo condensers 5 and 20, connected in series across the terminals of thelamp 4.

In Fig. 3 l. have shown in diagram the theoretical curve illustrative ofthe ditlerence of potential and the changes therein which may occur in acircuit such as shown in Fig. :2.

'hen the circuit is closed, there is a rise of potential at theterminals of the lamp from Each It is operation of the lamp may be moreor less zero to three thousand live hundred volts, as shown by theportion 1/ of the curve. Thereupon current traversing the lamp thecondenser discharges, dropping the current to one hundred volts, asindicated by the portion 7) of the curve. The voltage then again risesto three thousand live hundred volts, as indicated by the portion of thecurve, the rate of charging being dependent upon the amount ofself-induction or resistance in the circuit between the condenser andthe source. By varying this self-induction the portion (Z of the curvemay be made more or less abrupt, and by varying the inductive capacityof the circuit between the condenser and the lamp the portion 7/ of thecurve representing" the prolonged. The lines drawn above and below thezero-line near the end of Fig. 3 are designed to illustrate thegradually-decreasing surging-s of the comlenser-current during theinterval of discharge in its circuit.

By properly adjusting the capacity of the condenser, the circuit, andalso the inductance almost any required delinitc period of charge anddischarge may be secured. The condenser 5 may be made to act either byreason of its own natural period of oscillation or governed by thecharge which it receives from the line as controlled by the line. Thecontrol of the output of the source may be derived from the secondarycircuit of the transformer. the secondary coil thereof being adjusted inresonance rise with the primary, so that the oscillations in thesecondary circuitmay be capable of preponderating the periodicity of thesystem.

The currents developed in the circuit and hereinbefore described asutilized for increasing the luminosity of one of my lamps may inaddition be used for other purposes, or the quality of my apparatus as alight-giving body may be fully subservient to the developmcntof currentsfor other purposes. In othe 1' words, I may in some instances constructa gas or vapor apparatus having the primary object of controlling therate of currents developed in the system, which currents may or may notoperate to give light in theapparatus.

This application is a division of an application, Serial No. 104:,(308,tiled April 25, .1902, in which claims are made for certain features oftheapparatus herein described. ln another application, Serial No.10%,607, liled April 25, 1W2, claims are made upon certain of theconductive under the influence of currents of a given potential andremaining conductive under the influence of currents of a lesspotential, of asource of electric currents, and means for periodicallyapplying to the terminals of the lamp differences of potential varyingfrom the higher potential to a value less than said lesser potential,substantially as described.

2. The combination with a gas or vapor lamp having a gas or vapor pathcapable of being rendered conductive under the influence of currents ofa given potential, and remaining conductive under the influence ofcurrents of a less potential, of a source of electric currents, acondenser connected in parallel with the lamp, and a retarding deviceconnected between the source and the condenser, substantially asdescribed.

3. A source of electrical capacity, a dis-

